Question

The quadratic equation h(t)=-16.1t^2+150 models a balls height,in feet, over time, in seconds, after it is dropped from a 15 story building. How many seconds, rounded to the nearest hundredth, did the ball hit the ground?

Answer 1

`h(t)=-16.1t^(2)+150. \\ewline(d)/(dt)[h(t)=-16.1t^(2)+150] = h'(t) = -(161)/(10) \cdot (d)/(dt)[t^(2)] + (d)/(dt)[150] = 0-(161\cdot2t)/(10) = -(161t)/(5) = -32.2t \Rightarrow t = 32.2 \ s.`